1. Field of the Invention
The present invention relates to a catalyst tower and a chemical decontamination liquid decomposing system having the catalyst tower.
2. Description of the Prior Art
FIG. 6 is a view showing the structure of an example of a conventional catalyst tower. In this catalyst tower, a chemical decontamination liquid flowing out of an inlet pipe 11 is turned upward and distributed in a lower chamber 12, and after that, flows through an inlet mesh filter 13, and flows upward in a catalyst 14, and then flows through an outlet mesh filter 15 to be discharged through an outlet pipe 16. When the catalyst is charged in a catalyst tower container 18, the catalyst is charged by removing a catalyst tower upper lid 17 and the outlet mesh filter 15. Further, in order to prevent the catalyst from occurring convection inside the catalyst tower container 18 due to a gas produced by decomposition reaction of the chemical decontamination liquid, the outlet mesh filter 15 is constructed so as to push down the catalyst using springs 21. Therefore, the outlet mesh filter 15 needs to have a detachable and movable structure.
In order to made the structure of the outlet mesh filter 15 detachable and movable, it is necessary that gaps are provided both in a portion between the outer periphery of the outlet mesh filter 15 and the inner peripheral wall of the catalyst tower container 18, and in a penetration portion of the inlet pipe 11 of the outlet mesh filter 15. The gaps need to be made as small as possible from the viewpoint of preventing the catalyst from flowing out. Although the penetration portion of the inlet pipe 11 of the outlet mesh filter 15 can be eliminated by making the inlet pipe 11 so as to penetrate the side wall portion of the catalyst tower container 18, it is uneconomical because the height of the catalyst tower container 18 is increased and accordingly a shielding container for containing the catalyst tower 5 becomes larger. Further, another method of narrowing the gaps considered is that O-rings are provided in the outer periphery of the outlet mesh filter 15 and in a penetration portion of the inlet pipe 11, but in that case, the movability of the outer mesh filter 15 is decreased to deteriorate the function of pushing down the catalyst.
An object of the present invention is to provide a chemical decontamination liquid decomposing system having a catalyst tower which has a mesh filter capable of certainly preventing catalyst from flowing out and a mechanism of pushing-down the catalyst capable of preventing convection of the catalyst caused by decomposition gas.
One of embodiment to attain the above object is a catalyst tower which comprises an outlet mesh filter arranged between a catalyst for decomposing the chemical decontamination liquid and an outlet pipe for making the chemical decontamination liquid flow out of the catalyst tower; and a catalyst charging port for charging said catalyst, and the outlet mesh filter is arranged so as to closely attached to an inner surface of the catalyst tower and to an inner surface of the catalyst charging port; and a catalyst pushing-down mechanism for suppressing convection of the catalyst is arranged inside the catalyst charging port.
As a concrete structure, the catalyst charging port 19 is arranged in a catalyst tower upper lid 17, and the catalyst pushing-down mechanism 20 is arranged inside the catalyst charging port 19, as shown in FIG. 1. Further, the outlet mesh filter 15 has a structure closely attached to the inner wall of the catalyst tower container 18 and to the catalyst charging port 19.
According to this structure, the catalyst can be directly charged into the catalyst tower container 18 through the catalyst charging port 19, and accordingly there is no need to remove the catalyst tower upper lid 17 and the outlet mesh filter 15. Further, by arranging the catalyst pushing-down mechanism 20 inside the catalyst charging port 19, there is no need to form the outlet mesh filter 15 movable. By employing such a structure, there is no need to construct the outlet mesh filter 15 detachable and movable. Therefore, the outlet mesh filter 15 can be formed in the structure of closely attaching to the inner wall of the catalyst tower container 18 and to the catalyst charging port 19.
Consequently, it is possible to certainly prevent the catalyst from flowing out through the outlet mesh filter 15. Further, since the catalyst 14 can be certainly pushed down by the catalyst pushing-down mechanism 20 arranged inside the catalyst charging port 19, occurrence of convection of the catalyst caused by the decomposed gas can be prevented.
According to the present invention, it is possible to provide a catalyst tower which can prevent the catalyst from flowing out to the system, and can prevent convection of the catalyst caused by the decomposed gas generated in the catalyst tower from occurring, and to provide a chemical decontamination liquid decomposing system having the catalyst tower.